Late Holocene environmental and climatic changes in the Western Sayan Mountains based on high‐resolution multi‐proxy data

Abstract

Southern Siberia is characterized by complex climatic and vegetation patterns, and the late‐Quaternary evolution of climate and vegetation in this vast region is still poorly understood. This study uses pollen, spores, testate amoebae and plant macrofossils to characterize environmental and climatic changes at Bezrybnoe Mire (Western Sayan Mountains, southern Central Siberia). Pollen data indicate permanent forest cover in the region during the Late Holocene and subtle variations in abundances of dominant taxa (Pinus sibirica,Abies sibirica,Larix,Pinus sylvestris and Betula pendula). Higher values of Betula and Artemisia at the beginning of the record (>2500 cal. a BP, probably c. 3300 cal. a BP) and c. 420–140 cal. a BP suggest slight expansion of birch forest and steppe. The intervening period has higher values of dark taiga taxa, suggesting a shift to higher moisture levels. Superimposed on this longer‐term variation, the testate amoeba record of mire wetness reveals 12 sub‐millennial episodes of drier conditions (with a sample resolution of c. 50–90 years). Mire plant communities reacted to the high‐frequency fluctuations in moisture but with a delayed response of c. 30–40 years. Both the short‐ and long‐term variations in moisture show general concordance with neighbouring regional records and align with observed cultural changes of the Eurasian steppe region. These variations in moisture probably relate to the degree of penetration of the moisture‐bearing Westerlies into southern Siberia.